Pediatric Pulmonology Unit, Shaare Zedek Medical Center Affiliated to The Hebrew University, School of Medicine, Jerusalem, Israel.
Respiration. 2012;84(3):207-11. doi: 10.1159/000336554. Epub 2012 Mar 21.
Arterial hemoglobin oxygen saturation (SaO₂) decreases at an altitude of >1,500 m. There are no reports on normal SaO₂ at altitudes between 0 and 1,500 m. The clinical significance of decreased SaO₂ at such altitudes is unclear.
To test the hypothesis that in healthy volunteers normal SaO₂ at moderate altitude (MA; 725 m) is lower than that at almost sea level (SL; 43 m).
SaO₂ was measured by transcutaneous pulse oximetry in young healthy volunteers at MA and was compared to equivalent measurements at SL. In addition, a 6-min walk test was performed and SaO₂ at the end of the walk was compared between the two locations.
111 males were checked at MA and 101 at SL. At rest, nadir SaO₂ was 95% at MA compared to 97% at SL. Mean SaO₂ at rest was slightly higher at SL (98.53 ± 0.52) compared to MA (98.11 ± 0.8; p < 0.01). In subjects who completed the 6-min walk test, SaO₂ slightly decreased after the test in both locations, by 0.38 ± 0.65% in the SL group and by 0.37 ± 1.12% in the MA group. This difference is not statistically significant by univariate analysis; however, a multiple regression analysis indicated that the drop in SaO₂ was higher at MA than at low altitude.
We found a low but significant difference in SaO₂ between near-SL and at an altitude of 725 m. The clinical significance of this difference, in terms of human health, is probably minimal.
动脉血氧饱和度（SaO₂）在海拔>1500 米处下降。在 0 至 1500 米之间的海拔高度，SaO₂的正常数值尚未见报道。SaO₂在如此高海拔处下降的临床意义尚不清楚。
检验下述假说，即健康志愿者在中海拔（MA；725 米）的正常 SaO₂值低于近海平面（SL；43 米）。
通过经皮脉搏血氧饱和度仪在 MA 和 SL 处测量年轻健康志愿者的 SaO₂，并对两者进行比较。此外，还进行了 6 分钟步行试验，并比较了这两个位置的步行结束时的 SaO₂。
111 名男性志愿者在 MA 处检查，101 名男性志愿者在 SL 处检查。休息时，MA 的 SaO₂最低值为 95%，而 SL 为 97%。SL 处的平均 SaO₂在休息时略高于 MA（98.53±0.52%比 98.11±0.8%；p<0.01）。在完成 6 分钟步行试验的受试者中，SaO₂在两个位置测试后均略有下降，SL 组下降 0.38±0.65%，MA 组下降 0.37±1.12%。这一差异在单变量分析中无统计学意义；然而，多元回归分析表明，MA 组的 SaO₂下降幅度高于低海拔组。
我们发现，近海平面和海拔 725 米处的 SaO₂存在低但显著的差异。就人类健康而言，这种差异的临床意义可能很小。
